Pass through firestop device

ABSTRACT

A cast-in-place pass through firestop device for providing a passage in a partition through which wires, cables, pipes, and the like are run includes a housing having a riser portion with frangible connections that define removable bands that can be readily removed by a user to adjust the height of the device in accordance with the thickness of the partition into which the device is installed. The removable bands include pull tabs that provide grasping means to facilitate removal of the bands by a user along a frangible connection. The housing also includes a base portion including a recess with ribs for maintaining firestop material in spaced relation from the base portion sidewall. A flame retardant char forming material, which works in combination with the firestop material to provide a fire, smoke, and water barrier, may also be provided adjacent the firestop material.

FIELD OF THE INVENTION

The present invention relates generally to firestop devices and, moreparticularly, to a cast-in-place firestop device for passing cables,pipes, and the like through a concrete partition, such as a floor.

BACKGROUND OF THE INVENTION

During the construction of buildings, it is necessary to provideopenings or passages through the building floors, walls, and ceilings topermit the running of wires, cables, pipes, and the like. Such openings,however, which are often referred to as through-penetrations, provideone mechanism by which fire and smoke may spread from one compartment ofthe building to another.

Through-penetrations in poured concrete partitions may be formed byvarious techniques including knocking holes in the partition after ithas been formed, or using a device which is arranged on a concrete formbefore the concrete is poured. Such devices may include an intumescentfirestop material which expands and closes the opening in the partitionin the event of a fire, thereby preventing the spread of fire and smokefrom one compartment of the building to another. Such devices are oftenreferred to as cast-in-place pass through firestop devices.

Cast-in-place firestop devices for providing a through-penetration in apartition that use intumescent material to close the passageway andprevent the spread of fire and smoke in the event of a fire are known inthe patented art. The Harbeke U.S. Pat. No. 4,669,759, for example,discloses a firestop stack coupling including intumescent material whichexpands to close off a pipe passing through the coupling in the event ofa fire. The Harbeke U.S. Pat. No. 4,888,925 discloses a fire retardantfluid coupling assembly having a metallic band wrapped about anintumescent collar.

The Roth U.S. Pat. No. 5,347,767 discloses a smoke and fire protectiondevice for providing a heat sealable raceway for running wires andcables through a concrete wall, ceiling, or floor. The device includes athermally expansive material which, in the event of a fire, expandscausing the raceway to collapse, thus preventing fire and/or smoke frompassing through the wall, ceiling, or floor. The raceway slidably fitswithin a tubular housing allowing the raceway to extend through thesleeve to either side of the device, thereby allowing an installer tocouple additional sections of the raceway at a convenient locationremote from the device. The sleeve has a length sized to accommodate thethickness of the particular mounting location. Since the sleeve is sizedto accommodate a particular partition thickness, the user mustpre-select the appropriate size sleeve for a particular job, therebyrequiring installers to keep a large number of different size devices onhand.

The Rejecki U.S. Pat. No. 5,390,465 discloses a pass through firestopdevice for installation in a building wall or floor to provide a passthrough opening for pipes, tubing, and the like. The device includes anaxially open first end and a tubular body having a second end closed bya transverse wall. A ring of intumescent material fills the axially openfirst end. The device is installed during the formation of the buildingpartitions by attaching the device to form elements and then pouring thefloor or wall structure. After the floor is poured, the upper endsection of the tubular body is removed by cutting it flush with theupper surface of the floor.

The Münzenberger et al. U.S. Pat. No. 6,161,873 discloses a masonrylead-in fixture having a housing including an axially extending throughbore, a radially protruding attachment flange provided at least at oneend of the housing, an intumescent material which, in case of fire,closes the bore, and a disc-shaped partition located in the housingwhich extends over the inner diameter of the bore which is broken whenpipe, cable, or the like is pushed through the fixture. The fixtureincludes a lengthening pipe formed of a plastic material that is cut-offto a desired length.

Thus, there remains a need in the industry for a cast-in-place passthrough device for providing a heat sealable passageway throughpartitions such as floors, walls, or ceilings in a structure such as abuilding for running cables, wires, pipes, and the like, that can bequickly and easily installed in partitions having varying thicknesses.In addition, there remains a need for such a device that allows forearly, fast, uniform, and complete expansion of the intumescent materialin case of a fire.

It would therefore be desirable to provide a cast-in-place pass throughfirestop device for providing a heat sealable passageway in a partitionthat can be used in partitions of various thicknesses, and which furtherallows the intumescent material to quickly and completely expand whenexposed to temperatures typically encountered during a fire.

SUMMARY OF THE INVENTION

The present invention provides a firestop device for providing a passagethrough a partition in a structure comprising a housing and firestopmaterial arranged within the housing, wherein the housing includes atleast one frangible connection transecting the housing. The termfirestop material refers generally to intumescent, endothermic, andablative materials useful in resisting the spread of fire and smoke fromone compartment of a structure to another.

The frangible connection can be formed in the housing by providing aline of weakness in the housing by, for example, scoring, notching, orcreasing the housing, or by molding or machining the housing to have athin region in the wall, thereby allowing a user to easily tear thehousing along the line of weakness. The frangible connection defines aremovable band that can be readily removed by a user, typically with theaid of a hand tool such as pliers, to shorten the length of the housingto accommodate the thickness of the partition into which the device isinstalled. The removable band preferably includes a pull tab thatprovides grasping means for a user to remove the band from the housingalong the frangible connection, thereby facilitating manual removal ofthe band.

In a specific embodiment, the housing includes a base portion and ariser portion, the base portion including a recess adapted to receivethe firestop material, and the riser portion including the frangibleconnection. The base portion includes a sidewall portion and a shoulderportion that combine to define the recess. The sidewall portion extendsfrom a first open end toward the riser portion, and the shoulder portionextends inwardly from the sidewall portion to the riser portion.

In one aspect of the invention, the sidewall and the shoulder portionsinclude inner surfaces having ribs. The sidewall ribs serve to maintainthe firestop material in the recess in spaced relation to the sidewall,thereby creating a gap between the firestop material and the sidewallthat allows heated air from a fire to more completely surround thefirestop material, thereby providing earlier, more uniform, and morecomplete expansion of the firestop material.

In one embodiment, a gasket is provided between the firestop materialand the shoulder portion to provide a seal that prevents water and smokefrom passing through the opening prior to expansion of the firestopmaterial. The shoulder portion rib helps retain the gasket in place.

In another aspect of the invention, the housing has first and secondopposed open ends and a hollow chamber having a longitudinal axisextending from the first open end to the second open end. The first openend is provided in the base portion and the second open end is providedin the riser portion. The firestop material is provided along thesidewall portion inner surface from the first open end to the shoulderportion.

In a more specific aspect of the invention, the housing has a two-tieredcylindrical shape with the base portion having a larger diameter thanthe riser portion. The base portion may also include a radiallyoutwardly extending flange extending outwardly from the periphery of thebase portion adjacent the first open end for fixing the device to aform. In one embodiment, the flange extends outwardly 360 degrees aroundthe base portion, and in another embodiment, two separate flangesextending radially outwardly from opposite sides of the base portion areprovided to allow for closer stacking of adjacent devices.

The riser portion preferably includes a plurality of equally sizedtransverse bands each including a manually engageable pull tab tofacilitate manual removal of the associated bands with or without theaid of a manually operated hand tool. By removing successive bands, auser can adjust the length of the device (i.e. shorten) in accordancewith the thickness of the partition into which the device is installed.It will be recognized that providing more bands will increase the rangeof partition thicknesses that can be accommodated by the device, andincreasing the number of bands per unit length will increase the abilityof the device to more closely match the thickness of the partition. Inaddition, the pull tabs on each band may be provided with indiciaindicating the length of the device at the band and corresponding to thethickness of the partition. Each band may also include one or moreradially outwardly extending circumferential ribs that provide the bandsand, consequently, the riser with added hoop strength, and also providea projection for making snap connections.

In another aspect of the invention, the device includes a cap that isattached to the riser portion of the device to cover the second openend. In one embodiment, the cap includes cantilevers that snap onto thecircumferential ribs, thereby securely attaching the cap to the riserportion. The firestop device may also include an extension memberadapted to connect with the riser portion to increase the length of thedevice and allow the device to be used with partitions havingthicknesses greater than the standard length of the device. The outerdiameter of the extension is preferably sized so that standard sizeplastic pipe can fit over and connect with the extension to provideadditional extension for the device.

In another aspect of the invention, the device includes a retaining ringarranged within the base portion first open end adjacent the firestopmaterial that serves to retain the firestop material in the baseportion. The retaining ring may be coded with color or other indicia toindicate the quantity of firestop material provided in the device which,in turn, corresponds with the application of the device. An adapter mayalso be provided that connects with the base portion to allow the deviceto be coupled to a contoured surface such as a fluted or corrugateddeck.

In a specific embodiment, the present invention provides a firestopdevice for providing a passage through a partition in a structurecomprising a housing having first and second opposed open ends and ahollow chamber having a longitudinal axis extending from the first openend to the second open end, the housing including a cylindrical baseportion having a diameter and a cylindrical riser portion having adiameter smaller than the base diameter, the base portion including anannular sidewall portion extending from the first open end toward theriser portion and a shoulder portion extending radially inwardly fromthe sidewall portion to the riser portion, the sidewall portion and theshoulder portion defining an annular recess for receiving firestopmaterial, the sidewall and the shoulder portions including innersurfaces having inwardly extending ribs, the riser portion including aplurality of longitudinally arranged frangibly connected circumferentialbands having equal axial lengths, each band including a radiallyoutwardly extending pull tab that can be used to remove an associatedband from the riser portion along a frangible connection, thereby toreduce the height of the device in accordance with the thickness of thepartition into which the device is installed.

In another aspect of the invention, which is particularly useful forwhen a metal pipe is passed through the device, a flame retardant charforming material is provided within the housing adjacent the firestopmaterial, preferably adjacent the inner surface of the firestopmaterial. In a specific embodiment, the flame retardant char formingmaterial is an annular band arranged concentrically within the firestopmaterial. The flame retardant char forming material serves to strengthenthe expanded intumescent material such that the resulting mass forms afire barrier that can pass the hose stream portion of ASTM E 814 FireTest Standard.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be further described with reference to theaccompanying drawings, in which:

FIG. 1 is a perspective view of a firestop device according to theinvention;

FIG. 2 is a bottom view of the housing;

FIG. 3a is a sectional view taken along line 3 a—3 a in FIG. 2;

FIG. 3b is a sectional view taken along line 3 b—3 b in FIG. 2 showingthe device with firestop material arranged therein;

FIG. 4 is a detailed sectional view taken along line 4—4 of FIG. 1;

FIG. 5 is an exploded perspective view of the device showing a cap, anextension member, and an adapter;

FIG. 6 is a sectional view showing the device installed in a concretefloor; and

FIG. 7 is a sectional view of an alternate embodiment of the inventionshowing a pipe passing through the device.

DETAILED DESCRIPTION

Referring now to the drawings, wherein like reference numerals refer tolike or corresponding parts throughout the several views, FIGS. 1-6 showa cast-in-place pass through firestop device 2 for providing athrough-penetration in a floor, wall, ceiling, or the like. The termthrough-penetration generally refers to an opening in a floor, wall,ceiling, or the like, which allows cables, wires, pipes, or other itemsto pass from one compartment of a structure to another. To create athrough-penetration using the device 2, the device is secured to awooden concrete form 46 (FIG. 6) or other surface such as a fluted deckusing an adapter 40 (FIG. 5), and concrete is poured into the form,thereby embedding the device 2 in the concrete 44.

The device 2 includes a generally cylindrical hollow housing 4 having anopen first end 6, an open second end 8, a chamber 10 extendinglongitudinally from the first end 6 to the second open end 8, andintumescent firestop material 26 (FIGS. 3b, 6 and 7) arranged in thedevice 2 adjacent the first open end 6. It will be recognized that thehousing 4 may have a shape other than cylindrical. For example, thehousing 4 may have a square or rectangular cross section.

The housing 4 includes a base portion 4 a having a longitudinallyextending annular side wall 14 extending from the open first end 6toward the open second end 8, radially outwardly extending flangeportions 15 extending outwardly in opposite directions from the baseportion 4 a adjacent the open second end 8, a radially inwardlyextending shoulder portion 17 extending inwardly from the sidewall 14,and a riser portion 4 b having a longitudinally extending annular sidewall 16 extending from the shoulder portion 17 to the second open end 8.The base portion 4 a has a larger diameter than the riser portion 4 bgiving the housing 4 a two-tiered tapered configuration in which thebase portion 4 a has a greater cross-sectional area than the riserportion 4 b.

In accordance with a characterizing feature of the invention, the riserportion 4 b includes a plurality of circumferential bands 18 a-dconnected by frangible connections 20 a-d. The frangible connections 20a-d allow one or more bands 18 a-d of the riser 4 b to be quickly,easily, accurately, and cleanly removed by a user, typically with theaid of a manually operated hand tool such as pliers, at pre-selectedintervals so the device 2 can be used in partitions having a variety ofthicknesses.

Each band 18 forms a continuous 360 degree loop which forms a section ofthe riser portion 4 b that can be readily removed by a user to shortenthe riser portion 4 b and thereby match the thickness of the partitioninto which the device is installed. Each band 18 includes a pair ofcircumferential ribs 18 a′ (FIG. 4) that provide hoop strength andprovide means for forming a snap connection with the riser portion 4 b.The frangible connections 20 a-d are lines of weakness formed by, forexample, molding or machining the riser to have thin areas of materialconnecting adjacent bands 18 a-d that can be manually broken by a userto separate adjacent bands.

Each band 18 a-d includes a pull tab 22 a-d extending radially outwardlyfrom the bands 18 a-d. The pull tabs 22 a-d facilitate removal of theassociated bands 18 a-d by providing grasping means for a user to graspand pull, typically with the aid of a hand tool such as pliers, therebytearing the associated frangible connection to remove the band from theriser 4 b. Each pull tab 22 a-d may be marked with indicia indicatingthe length or height of the device at that pull tab corresponding to thethickness of the partition.

The base portion 4 a contains an annular recess 24 for receivingfirestop material 26 (FIGS. 3b, 5, 6 and 7). The firestop material 26 isprovided in the form of an annular ring as shown in FIG. 5 that extendsalong the inner surface of the sidewall portion 14 from the first openend 6 to the shoulder portion 17. The firestop material 26 may be heldin place in the recess 24 with adhesive, using mechanical fasteners, orby using a retaining ring 38 (FIG. 5) described more fully below. Tofacilitate the installation of a pipe through the device 2, the innersurface of the firestop material 26 if preferably aligned with the innersurface of the riser portion 4 b, that is, the inner diameter of thefirestop material 26 and the riser 4 b are the same, whereby thediameter of the chamber 10 is generally the same along the entire lengthof the device 2.

The recess 24 is defined by the sidewall portion 14 and the shoulderportion 17 of the base portion 4 a. In accordance with anothercharacterizing feature of the invention, the inner surfaces of thesidewall portion 14 and the shoulder portion 17 facing the chamber 10include rib portions 14 a and 17 a, respectively. The sidewall ribs 14 aextend radially inwardly from the sidewall 14 and extend longitudinallyfrom adjacent the flange 15 to the shoulder portion 17. The shoulderportion rib 17 a is an annular projection extending outwardly from theshoulder portion 17 in the direction of the first opening 6. The sidewall portion ribs 14 a maintain the firestop material 26 in spacedrelation from the sidewall portion 14 and create an air gap 27 betweenthe firestop material 26 and the side wall portion 14 which, in theevent of a fire, allows the entire axial length of the firestop materialto be exposed to heated air, thereby aiding rapid, complete, and uniformexpansion of the firestop material which in turn closes thethrough-penetration.

Referring now to FIG. 5, the device 2 is provided with a cap 28 thatattaches to the riser portion 4 b and covers the second open end 8. Thecap 28 prevents concrete being poured during the formation of apartition from entering the device 2. The cap 28 includes snapconnectors 30 that allow the cap to be manually snap fit onto the riserportion 4 b via the circumferential ribs 18 a′.

The device 2 may also be provided with an extension member 32 thatattaches to the top of the riser portion 4 b adjacent the open secondend 8. The extension member 32 contains cut-outs 34 aligned with tabs 22a-d on the riser portion 4 b that allow the extension member 32 to beplaced in overlapping relation with the riser portion 4 b. The extensionmember 32 also includes snap connections 36 that allow the extension tobe attached to the riser portion 4 b. The extension member 32 serves toincrease the height of the device 2 and thereby allows the device 2 tobe used in partitions in which the thickness of the partition is greaterthan the standard height of the device 2. The extension member 32 isalso preferably sized so that standard size plastic pipe can fit overthe top of the extension member 32 to provide further extension. Thatis, the outer diameter of the extension member 32 corresponds to theinner diameter of a standard size plastic pipe, whereby the plastic pipeis adapted to fit over the extension member 32.

The device includes an annular gasket 37 arranged in the recess 24between the firestop material 26 and the shoulder portion 17. The gasket37 is formed of an elastomeric material and serves to form a smoke andwater seal at ambient conditions with the pipe installed prior toexpansion of the firestop material. The device 2 is also provided withan annular retaining ring 38 that attaches to the base portion 4 a ofthe device and retains the firestop material 26 in the device 2. Theretaining ring 38 includes tabs 39 to facilitate attachment of theretaining ring 38 to the base portion 4 a. The tabs 39 are aligned withand extend through slots 41 provided in the base portion 4 a. Once theretaining ring 38 is installed in the device 2, the tabs 39 are bentoutwardly to secure the retaining ring 38 in place and also anchor thedevice 2 in the concrete after the concrete is poured.

Since the quantity of firestop material 26 provided in the device 2 willvary depending on the type of installation (for example, more firestopmaterial will be provided in the device when it is used with a plasticpipe than a metal pipe), the retaining ring 38 may be provided withcolor coding to indicate the quantity of firestop material installed inthe device and/or the type of pipe in the installation. This way, afterthe device has been installed in a partition, the quantity of firestopmaterial and the type of installation (i.e. a plastic pipe or a metalpipe installation) can be quickly and easily identified by visualinspection, eliminating the need to remove the retaining ring to makesuch a determination.

In addition, the device 2 may be provided with an adapter 40 thatattaches to the base portion flange 15 and allows the device 2 to beused on contoured surfaces such as a fluted deck. The adapter 40includes a hollow tubular extension portion 40 a, an outwardly extendingflange portion 40 b, and snap connectors 42 that snap connect with thebase portion 4 a of the device 2.

While the device may be formed from a variety of materials, the device 2is preferably formed of a synthetic plastic material such aspolyethylene. The firestop material 26 may include an intumescentcompound, an endothermic compound, or both an intumescent compound andan endothermic compound. Exemplary intumescent compounds includeintumescent graphite such as intercalated graphite and acid treatedgraphite, hydrated alkali metal silicates, vermiculite, perlite, andNaBSi. Exemplary endothermic compounds include aluminum trihydrate(ATH), Al(OH)₃ hydrated zinc borate (ZnB₂O₄.6H₂O), calcium sulfate(CaSO₄.2H₂O) also known as gypsum, magnesium ammonium phosphate(MgNH₄PO₄.6H₂O), magnesium hydroxide (Mg(OH)₂), encapsulated H₂O, andmagnesium ammonium phosphate hexahydrate, MgO.2B₂O₃.9H₂O. A preferredfirestop material 26 is INTERAM Ultra GS Graphite mat available from 3MCompany, St. Paul, Minn.

Referring to FIG. 6, the device 2 is shown installed in a concrete floor44. The device 2 is installed by first securing the device 2 to a woodenconcrete form 46 with fasteners 48, and then pouring concrete into theform 46, thereby embedding the device in the concrete. The cap 28 isthen removed and any unnecessary bands 18 a-d are removed by graspingand pulling the pull tabs 22 a-d. It will also be recognized that if thethickness of the partition is known, excess bands can be removed priorto installation.

Referring to FIG. 7, there is shown a cast-in-place pass throughfirestop device 2 installed in a concrete floor 44 with the form 46shown in FIG. 6 removed and a metal pipe 62 passing through the device2. The firestop device 2 in FIG. 7 is similar to the one shown in FIG. 6except it further includes a flame retardant char forming insert 64arranged between the intumescent firestop material 26 and the metal pipe62. It has been found that by providing a flame retardant char formingmaterial between the intumescent material 26 and the pipe 62, a firebarrier capable of passing the hose stream portion of the ASTM E814 teststandard is created. Providing the char forming insert 64 isparticularly useful when the device 2 is used to firestop a metal pipepassing through an opening in a floor.

The insert 64 can be a continuous annular band that is secured withinthe device 2 using adhesive, mechanical fasteners, or the retaining ring38 described above. Alternatively, the insert 64 can be a discontinuousarcuate band that can be compressed like a spring clip so that theinsert can be positioned within the intumescent material 26 and held inplace by the spring force.

The insert 64 is formed of a flame retardant material (i.e. one thatdoes not support combustion) that does not melt and which forms a charwhen exposed to high temperatures such as those encountered in a fire.In this manner, insert 64 works in combination with the expandedintumescent material 26 to provide a fire, smoke, and water barrier inthe annular space around the metal pipe that enables the device to passthe hose stream portion of the ASTM E814 test standard.

The particular material selected for the insert 64 is not critical tothe invention hereof, so long as it provides the desired function.Suitable flame retardant materials that form a char include halogenatedpolymers such as polychloroprene, polyvinyl chloride and polyvinylidenefluoride; chlorine flame retardant compounds such asperchloropentacyclodecane and chlorinated paraffins; bromine flameretardant compounds such as decabromodiphenyl oxide, octabromodiphenyloxide, and tetrabromodipentaerythritol; phosphorous compounds such asammonium polyphosphate and tributylphosphate; compounds including bothchlorine and phosphorous such as 1,3dichloro-2-propanol phosphate and2-chloroethanol phosphate; and nonhalogenated polymers such as hydratedzinc borate and boric oxide. A preferred flame retardant char formingmaterial for the insert is polyvinyl chloride.

The patents, patent documents, and patent applications cited herein areincorporated by reference in their entirety as if each were individuallyincorporated by reference. It will be apparent to those of ordinaryskill in the art that various changes and modifications may be madewithout deviating from the inventive concept set forth above. Forexample, it will be recognized that the device may also includestabilizers to prevent rotational or axial movement of the device afterthe device has been installed in a floor, ceiling, wall, or the like.Thus, the scope of the present invention should not be limited to thestructures described in this application, but only by the structuresdescribed by the language of the claims and the equivalents of thosestructures.

What is claimed is:
 1. A firestop device comprising: (a) a housing; (b)firestop material arranged within said housing; and (c) a flameretardant char forming material arranged within said housing adjacentsaid firestop material.
 2. A firestop device as defined in claim 1,wherein said flame retardant char forming material is arranged withinsaid firestop material.
 3. A firestop device as defined in claim 2,wherein said flame retardant char forming material is an annular bandarranged concentrically within said firestop material.
 4. A firestopdevice as defined in claim 3, wherein said flame retardant char formingmaterial is polyvinyl chloride.
 5. A firestop device comprising: (a) acylindrical housing including a base portion having an annular recessand a riser portion including a plurality of frangibly connectedcircumferential bands each including a pull tab that can be used tomanually remove a band from said riser portion along a frangibleconnection; (b) firestop material arranged within said base portionannular recess; and (c) a flame retardant char forming material arrangedwithin said base portion annular recess within said firestop material.